The definition and practical use of units of measure play a significant role in human business and commercial activities. Units of measure define magnitude of physical quantities. They are adopted by different conventions as a standard form for measurement of the same physical quantity. There are different systems that provide their own definitions for units of measure, for example, the Imperial System of Units, the Metric System, or the International System of Units (SI). The Unified Code for Units of Measure (UCUM) is a system of codes for unambiguous presentation of units of measure, which may be used by humans and machines. The UCUM includes all units of measures that are used in international science, engineering, and business. The usage of such systems may facilitate the unambiguous communication of quantities together with their units. Most importantly, this communication may be an electronic communication between machines (computers). Units of measure may be used when defining length, temperature, energy, time, pressure, currencies, etc. The variety of units is a challenge for both systems that process data containing units and users of such systems, since the wrong usage of data (e.g., mixing metric and imperial units for calculation) can lead to wrong results and critical errors.